For those of you who are looking to edit AVCHD video I cannot recommend this software enough. I purchased Vegas 9 to edit video shot on my Canon HG10 AVCHD camcorder after being disappointed with Nero Ultimate (the renderings had interlacing problems in non-still shots). Being new to video editing, I didn't find the interface in Vegas very intuitive at first. However, after watching a few youtube tutorial videos I became quite comfortable in the environment. Also, Vegas 9 has some built-in tutorials for basic editing that I found quite helpful.
Don't just take my word for it, you can TRY it first for 30 days if you download the trial from Sony's website. I have a pretty powerful computer (Quad core, 4G RAM, 9800 GTX) so you might want to test it on your system before purchasing for AVCHD editing.